Urology Journal

Abstract

Purpose: High mobility group box (HMGB) proteins are nuclear nonhistone chromosomal
proteins that bend DNA, bind preferentially to distorted DNA structures, and promote the assembly
of site-specific DNA binding proteins. Recent reports indicate that HMGB1 functions
as a proinflammatory cytokine. Here, we studied expressions of HMGB1 and HMGB2 in human
renal cancer.
Material and Methods: Immunohistological expressions of HMGB1 and HMGB2 were assessed
in 39 surgically resected human renal cancer specimens.
Results: HMGB1 was expressed in the nucleus in 37 out of 39 (94.9%) renal clear cell cancers,
while its expression in the cytosol was noted in 19 cases (48.7%). Cytosolic HMGB1 is
expressed more frequently in cancers beyond the pT1b classification than in those at the pT1a
classification. Higher tumor grades (≥ G2) were also significantly linked with the cytosolic
expression of HMGB1. HMGB2 was expressed in the nucleus in 35 of 39 (89.7%) renal clear
cell cancers, while its expression in the cytosol was observed in only 7 case (17.9%). Linkage
between cytosolic expression of HMGB2 and T classifications was weakly observed, while that
between nuclear expression and T classifications was not.
Conclusion: HMGB1 expressed in the cytoplasm may be an effective marker indicating higher
T classifications and tumor grades.